zbMATH — the first resource for mathematics

Geometry Search for the term Geometry in any field. Queries are case-independent.
Funct* Wildcard queries are specified by * (e.g. functions, functorial, etc.). Otherwise the search is exact.
"Topological group" Phrases (multi-words) should be set in "straight quotation marks".
au: Bourbaki & ti: Algebra Search for author and title. The and-operator & is default and can be omitted.
Chebyshev | Tschebyscheff The or-operator | allows to search for Chebyshev or Tschebyscheff.
"Quasi* map*" py: 1989 The resulting documents have publication year 1989.
so: Eur* J* Mat* Soc* cc: 14 Search for publications in a particular source with a Mathematics Subject Classification code (cc) in 14.
"Partial diff* eq*" ! elliptic The not-operator ! eliminates all results containing the word elliptic.
dt: b & au: Hilbert The document type is set to books; alternatively: j for journal articles, a for book articles.
py: 2000-2015 cc: (94A | 11T) Number ranges are accepted. Terms can be grouped within (parentheses).
la: chinese Find documents in a given language. ISO 639-1 language codes can also be used.

a & b logic and
a | b logic or
!ab logic not
abc* right wildcard
"ab c" phrase
(ab c) parentheses
any anywhere an internal document identifier
au author, editor ai internal author identifier
ti title la language
so source ab review, abstract
py publication year rv reviewer
cc MSC code ut uncontrolled term
dt document type (j: journal article; b: book; a: book article)
The zeros of az 2 J ν '' (z)+bzJ ν ' (z)+cJ ν (z) as functions of order. (English) Zbl 0763.33002

L. Lorch and P. Szego, furthermore R. Wong and T. Lang have shown quite recently, in two connected papers on the positive zeros j νk '' (k=1,2,) of the Bessel function J ν '' (x), that j νk '' is an increasing function of the order ν in the range ν>0 [see L. Lorch and P. Szego, Can. J. Math. 42, No. 5, 933-948 (1990; Zbl 0716.33003) and ibid. 43, No. 3, 628-651 (1991; Zbl 0731.33001)]. The present note aims to extend the result just mentioned to positive zeros of an expression of the form

az 2 J ν '' (z)+bzJ ν ' (z)+cJ ν (z)

as function of ν, where a, b, c are certain real numbers subjected to suitable mild restrictions.

33C10Bessel and Airy functions, cylinder functions, 0 F 1